Don't let a failing initial fetch block the socket/polling fallback

onMounted awaited the initial REST calls before setting up the socket and the
6s polling fallback, so any rejected request aborted the handler and left the
badge stuck on "connecting". Set up the socket and fallback first, make the
initial loads best-effort, and log [ws] connect/open/close for debugging.

frontend/src/api.js

@@ -48,6 +48,7 @@ export function openSocket({ onMessage, onOpen, onClose, onError }) {
     if (closed) return
     let opened = false
     let reported = false
+    console.debug('[ws] connecting to', url)
     socket = new WebSocket(url)
 
     // Report at most one failure per attempt (Safari often fires error *and*
@@ -72,11 +73,13 @@ export function openSocket({ onMessage, onOpen, onClose, onError }) {
       opened = true
       clearTimeout(openTimeout)
       attempt = 0
+      console.debug('[ws] open')
       onOpen?.()
     }
     socket.onmessage = (event) => onMessage?.(JSON.parse(event.data))
     socket.onclose = (event) => {
       clearTimeout(openTimeout)
+      console.debug('[ws] close', event.code, event.reason)
       onClose?.()
       if (!opened) {
         // 1008 = policy violation (token rejected); 1006 = abnormal close.